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At least 19 recordsLinked to original sources
PubMed1992

Major histocompatibility complex (MHC) antigen expression in HIV encephalitis.

In order to study possible immunopathogenic mechanisms in Human Immunodeficiency Virus (HIV) encephalitis, immunocytochemical localization of Class I and Class II major histocompatibility complex (MHC) antigens was studied in formalin-fixed tissue sections from the brains of 10 individuals who had died with this disorder. Using the avidin biotin peroxidase technique and monoclonal antibodies to these antigens, increased expression of Class I antigens was found in five out of 10 and of Class II antigens in six out of 10 cases of HIV encephalitis. This contrasted with results obtained with the HIV-specific anti-P24 antibody which reacted with only a small number of cells in four cases. Class I and II antigens were detected mainly in perivascular monocytes/macrophages and also in multinucleated giant cells. In two cases, slight labelling was also detected in these cells more diffusely in the brain parenchyma. Immune and viral antigens were not detected in glial cells or neurons. Neither normal control cases nor brain sections from patients who had died from other neurological diseases were labelled with any of the antibodies apart from two cases of varicella-zoster virus-associated encephalitis in which increased expression of Class II antigens occurred. These findings support the notion that indirect immune-mediated mechanisms may be important in the pathogenesis of HIV encephalitis.

Encephalitis↗
PubMed1992

Major histocompatibility complex (MHC) control of CD4 T cell subset activation. II. A single peptide induces either humoral or cell-mediated responses in mice of distinct MHC genotype.

CD4 T cells activated in vivo in response to human collagen type IV (hCol IV) resemble either T helper type 1 (Th1) or Th2 cells depending on the major histocompatibility complex (MHC) class II genotype of the responding mice. H-2s mice were shown to selectively activate Th1-like cells, releasing interleukin (IL 2 and interferon-gamma in response to hCol IV, whereas H-2b.d mice were shown to selectively activate Th2-like cells, releasing IL 4 and IL 5 in response to hCol IV. These results suggested that MHC class II regulated the type of effector function observed during an immune response. It was of interest to determine if the functional difference observed between the CD4 T cells of the two strains was due to the presentation of different peptides of the hCol IV molecule by the two MHC class II molecules. The present results demonstrate that a single peptide of the collagen IV molecule will elicit a Th1-like response in H-2s strains and Th2-like responses in H-2b.d strains, as was observed when using the intact hCol IV molecule. Furthermore, the failure to generate Th1-like responses in H-2b.d could be overcome by increasing the dose of this peptide in vitro. Compared to H-2s, the Th1-like response in H-2b required 100 times the amount of peptide to reelicit an equivalent response. These data suggest that a single peptide of hCol IV can control the type of effector response observed.

Amino Acid Sequence↗
PubMed1992

Major histocompatibility complex (MHC)-encoded HAM2 is necessary for antigenic peptide loading onto class I MHC molecules.

The mutant murine lymphoma cell line RMA-S is unable to present endogenous antigens due to its inability to efficiently assemble class I major histocompatibility complex molecules and antigenic peptides. Therefore, it has been suggested that RMA-S cells are defective either in peptide generation or in peptide transport into the endoplasmic reticulum, where class I major histocompatibility complex molecule assembly is believed to occur. As proteasomes and the putative peptide transporters HAM1 and HAM2 have been implicated in class I antigen processing, we have investigated their expression in RMA-S and its wild-type counterpart RMA. Both proteasomes and HAM1 proteins are expressed at similar levels and show identical subcellular distributions in the two cell lines. However, only one copy of the HAM2 gene is present in RMA-S cells, and it contains a point mutation that leads to a premature stop codon. Thus, the HAM2 protein is absent from RMA-S cells. These data demonstrate that HAM2 is essential for peptide loading onto class I molecules.

Amino Acid Sequence↗
PubMed1977

Graft-versus-host reaction. Influence of genetic background in donor-recipient pairs incompatible for major histocompatibility complex (MHC).

In two H-2b anti-H-2d but not in H-2b anti-H2k donor-recipient combinations, graft-versus-host reaction (GVHR) mortality was found to vary as a function of the host's genetic background; the same non-major histocompatibility complex genes and/or antigens which influence GVHR mortality do not influence the intensity of GVHR splenomegaly or the time of skin rejection. In contrast, the severity of GVHR mortality correlates with the intensity of stimulation in mixed lymphocyte culture. The roles of minor histocompatibility (H) antigens and Mls product are discussed.

Animals↗
PubMed2026

Influence of Major Histocompatibility Complex (MHC) Diversity on Immune Modulation, Pathogenesis, and Control of Lumpy Skin Disease Virus.

INTRODUCTION: Lumpy Skin Disease Virus (LSDV), a member of the genus Capripoxvirus within the family Poxviridae, is an economically important transboundary viral pathogen affecting cattle and water buffalo. The disease causes severe production losses through decreased milk yield, infertility, hide damage, reduced growth performance, and occasional mortality. The rapid geographic spread of LSDV, together with its vectorborne transmission and emerging recombinant strains, has intensified the need for improved understanding of viral pathogenesis, host immune responses, and effective prevention strategies. In particular, the role of the bovine Major Histocompatibility Complex (BoLA/MHC) in regulating antiviral immunity, disease susceptibility, and vaccine responsiveness has gained increasing scientific attention. METHODS: This review summarises the published literature related to the epidemiology, transmission, structure, pathogenesis, diagnosis, prevention, and control of LSDV, with special emphasis on the immunological and molecular role of bovine MHC molecules. Relevant studies concerning BoLA-mediated antigen presentation, immunoinformaticsbased epitope prediction, vaccine development, antiviral drug repurposing, molecular docking, genomic surveillance, and diagnostic approaches, including PCR- and ELISAbased assays, were critically evaluated. Recent advances in computational biology, molecular virology, and host-pathogen interaction studies were also reviewed. RESULTS: The reviewed studies demonstrate that Lumpy Skin Disease Virus (LSDV) possesses a complex double-stranded DNA genome enabling immune modulation and efficient transmission through arthropod vectors such as mosquitoes, ticks, and biting flies. Disease progression involves systemic viral replication, vascular injury, dermal necrosis, and inflammatory skin lesions. Real-time PCR remains the most sensitive diagnostic method for early detection, while ELISA supports surveillance. Evidence highlights the central role of bovine Major Histocompatibility Complex (BoLA) molecules in antigen presentation and T-cell activation. Computational studies identified promising BoLA-binding epitopes and repurposed antiviral candidates, including ivermectin, theaflavin, canagliflozin, and tepotinib, for future therapeutic development. DISCUSSION: Current evidence indicates that effective LSDV control requires integration of molecular diagnostics, vector management, vaccination, and host immunogenetics. BoLAguided immunoinformatics provides promising opportunities for developing multi-epitope vaccines, although experimental validation remains essential. Similarly, repurposed antiviral candidates require comprehensive in vivo and pharmacological evaluation before clinical application. Future research should focus on elucidating viral immune-evasion mechanisms, validating predicted epitopes, and translating computational findings into practical vaccines and therapeutics for sustainable disease control. CONCLUSION: Lumpy Skin Disease continues to pose a major threat to global cattle health and livestock economies. Advances in molecular diagnostics, genomic surveillance, antiviral drug discovery, and BoLA-guided vaccine design provide promising opportunities for improved disease control. Understanding the interaction between LSDV and the bovine MHC system is essential for developing next-generation vaccines, immunotherapeutics, and precision disease-management strategies. Future research should prioritise experimental validation of predicted epitopes, large-scale vaccine trials, and mechanistic studies on host-virus immune interactions to establish effective and sustainable global control programs for LSDV.

BoLA↗
PubMed1976

Linkage of gene for C2 deficiency and the major histocompatibility complex MHC in man. Family study of a further case.

Close linkage between HL-A and C2 deficiency was first reported by FU and co-workers in 1974. We present here a pedigree of a 31-year-old C2-deficient individual with clinical manifestations of Hodgkins disease. The following markers were tested: C2 levels, factor B polymorphism, blood groups, and enzyme typing. In addition to close linkage between HL-A and C2 deficiency, both parents were heterozygous for Bf (HL-A linked, electrophoretic variation of B). The two HL-A haplotypes closely linked to C2 deficiency are different: 2, W18 and W24, W18. They share, however, the SD2 antigen W18 and the LD type 7a.

Adult↗
PubMed1992

Biology of the chicken MHC (B complex).

The major histocompatibility complex (MHC) of chicken is the B complex, originally described as a blood group system. Its three classes of cell membrane antigens have been clearly defined by serological, histogenetic, biochemical, and molecular biological methods. Two of these classes are homologous to classes I and II of mammals (B-F and B-L respectively), while the third--B-G antigen--has not so far been detected in mammals. The possible role of this antigen is discussed. The genes of the MHC play important roles in the regulation of immune response, disease resistance, and regression of Rous sarcomas.

Animals↗
PubMed1979

Close association between particular I region-determined cell surface antigens and Ir gene-controlled immune responsiveness to synthetic polypeptides in wild rats.

The relationship between major histocompatibility complex (MHC) and genetic control of immune responsiveness to the synthetic polypeptides (T,G)-A--L [poly-(LTyr,LGlu)-poly(DLAla)--poly(LLys)] and (H,G)-A--L [poly(LHis,L-Glu)-poly-(DLAla)--poly(LLys)] has been studied in 26 wild rats. The major histocompatibility complex (MHC) genotype frequencies observed were not different from those expected according to the Hardy-Weinberg formula. More than half of the wild rats carried MHC-linked responder Ir-TGAL and Ir-HGAL genes. High or intermediate responsiveness to (T,G)-A--L and high responsiveness to (H,G)-A--L were always found to be associated with particular I region-determined cell surface antigens. These antigens could be identified serologically and by primary and secondary mixed lymphocyte reactions, and were similar or identical to I region products of (T,G)-A--L high responder or (H,G)-A--L intermediate responder inbred rat strains. The strong association between cell surface antigens and immune responsiveness could be due to linkage disequilibrium or to pleiotropy. Since the same I region-determined cell surface structure could be associated either with high or intermediate anti-(T,G)-A--L antibody titers, the presence of the Ia antigen(s) identified did not seem to guarantee high antibody responsiveness to the test antigen.

Animals↗
PubMed1992

Emerging principles for the recognition of peptide antigens by MHC class I molecules.

Class I major histocompatibility complex (MHC) molecules interact with self and foreign peptides of diverse amino acid sequences yet exhibit distinct allele-specific selectivity for peptide binding. The structures of the peptide-binding specificity pockets (subsites) in the groove of murine H-2Kb as well as human histocompatibility antigen class I molecules have been analyzed. Deep but highly conserved pockets at each end of the groove bind the amino and carboxyl termini of peptide through extensive hydrogen bonding and, hence, dictate the orientation of peptide binding. A deep polymorphic pocket in the middle of the groove provides the chemical and structural complementarity for one of the peptide's anchor residues, thereby playing a major role in allele-specific peptide binding. Although one or two shallow pockets in the groove may also interact with specific peptide side chains, their role in the selection of peptide is minor. Thus, usage of a limited number of both deep and shallow pockets in multiple combinations appears to allow the binding of a broad range of peptides. This binding occurs with high affinity, primarily because of extensive interactions with the peptide backbone and the conserved hydrogen bonding network at both termini of the peptide. Interactions between the anchor residue (or residues) and the corresponding allele-specific pocket provide sufficient extra binding affinity not only to enhance specificity but also to endure the presentation of the peptide at the cell surface for recognition by T cells.

Amino Acid Sequence↗
PubMed2025

Major histocompatibility complex class IIB disassortative mate choice in a genetically monogamous seabird.

Among species reproducing sexually, mating strategies represent a major component of individual fitness. The major histocompatibility complex (MHC) is an extremely diverse set of genes responsible for immunological recognition and defence against pathogens. Although dissimilarity between mates at the major histocompatibility complex has been proposed to drive mate choice through increased offspring pathogen resistance, evidence is mixed. In addition, explorations of the role of the major histocompatibility complex in other mating strategies, such as divorce, are rare. We investigated whether dissimilarity at the major histocompatibility complex class IIB is associated with mate choice and divorce probability in the genetically monogamous black-legged kittiwake (Rissa tridactyla). We found that first-time male breeders, as well as divorced males, were paired with females more dissimilar at the major histocompatibility complex class IIB than expected under random mating. We did not find evidence for mate choice based on major histocompatibility complex class IIB dissimilarity when considering females. In addition, in the studied population, divorce probability was very low compared with other populations and did not significantly vary with the dissimilarity of the pair at the major histocompatibility complex class IIB. Our results pave the way to a better understanding of the complex role of major histocompatibility complex dissimilarity in mating decisions of species displaying mutual choice and biparental care.

Animals↗
PubMed1992

Ancestral haplotypes reveal the role of the central MHC in the immunogenetics of IDDM.

The major histocompatibility complex (MHC) contains multiple and diverse genes which may be relevant to the induction and regulation of autoimmune responses in insulin dependent diabetes mellitus (IDDM). In addition to HLA class I and II, the possible candidates include TNF, C4, and several other poorly defined polymorphic genes in the central MHC region. This study describes two approaches which take advantage of the fact that the relevant genes are carried by highly conserved ancestral haplotypes such as 8.1 (HLA-B8, TNFS, C4AQ0, C4B1, DR3, DQ2). First, three "diabetogenic" haplotypes (two Caucasoid and one Mongoloid) have been compared and it has been shown that all three share a rare allele of BAT3 as well as sharing DR3, DQ2. In 43 sequential patients with IDDM the cross product ratio for BAT3S was 4.8 (p less than 0.01) and 6.9 for HLA-B8 plus BAT3S (p less than 0.001). Second, partial or recombinant ancestral haplotypes with either HLA class I (HLA-B8) or II (HLA-DR3, DQ2) alleles were identified. Third, using haplotypic polymorphisms such as the one in BAT3, we have shown that all the patients carrying recombinants of the 8.1 ancestral haplotype share the central region adjacent to HLA-B. These findings suggest that both HLA and non-HLA genes are involved in conferring susceptibility to IDDM, and that the region between HLA-B and BAT3 contains some of the relevant genes. By contrast, similar approaches suggest that protective genes map to the HLA class II region.

Adult↗
PubMed1992

Immunocytochemical observation of paraquat-induced alveolitis with special reference to class II MHC antigens.

The expression of class II major histocompatibility complex (MHC) antigens on alveolar epithelial cells and macrophages was investigated immunocytochemically in paraquat-induced alveolitis in the rat lung. Until 2 days after paraquat injection, class II MHC antigens were expressed on the type II alveolar epithelium without any inflammatory cellular infiltration. From the 4th to the 7th day after paraquat injection, class II MHC antigen-positive macrophages increased in the alveolar spaces, whereas the expression on the type II alveolar epithelium became obscure. Over 10 days after the injection, interstitial fibrosis progressed and the intra-alveolar inflammatory infiltrates decreased. Epithelial cells lining the thickened fibrous septa no longer expressed class II MHC antigens. These results suggest that chemical stimuli can induce class II MHC antigen expression on the type II alveolar epithelium in the early stage of cellular injury, followed by inflammatory infiltration and interstitial fibrosis.

Alveolitis, Extrinsic Allergic↗
PubMed1975

Cell mediated lympholysis in man. Varying strength of the HL-A (LA and FOUR) antigens as sensitizing or target determinants.

The gene products of the LA and FOUR loci of the human Major Histocompatibility Complex (MHC) are generally considered to be a major target in the Indirect Cell Mediated Lympholysis (ICML) test. Within most experiments, a positive correlation exists between the number of HL-A antigens challenged and lympholysis. When different experiments are collated this correlation is less obvious. This discrepancy might be caused by differences between the individual HL-A antigens involved in the afferent phase (MLC) and/or the efferent phase (CML). In 28 experiments involving 97 unrelated individuals we have compared statistically 12 different antigens governed by the LA and FOUR loci. When only one of these antigens is challenged in ICML, target lymphocytes are lysed to different degrees allowing a significant classification of the antigens into different groups, which do not coincide with the classification in the LA and FOUR series antigens. It is concluded that the antigens of the HL-A system are not of equal importance when challenged separately in ICML. The existence of a separate CML locus and a corresponding linkage disequilibrium to the SD loci of the MHC region is suggested.

Antigen-Antibody Reactions↗
PubMed2026

Identification of MHC Ligands Through Allele-Guided Isolation Combined With Machine Learning for Improved MHC Assignment Using ARDisplay-I.

The isolation of major histocompatibility complex (MHC) ligands and subsequent analysis by mass spectrometry is considered the gold standard for defining targets for T cell-based immunotherapies. However, as many targets of high tumor specificity are only presented at low abundance on the cell surface of tumor cells, the efficient isolation of these peptides is crucial for their successful detection. Here, we demonstrate how optimizing the MHC ligand isolation strategy, based on both the presenting MHC alleles and the individual peptide level, enhances the identification of specific MHC ligands. This ideally acknowledges not only the hydrophobicity but also the post-translational modifications of the respective MHC ligands. To further improve the identification and characterization of MHC ligands, we developed an MHC class I ligand prediction algorithm (ARDisplay-I) that outperforms current state-of-the-art tools when benchmarked against competitors such as netMHCpan 4.1, MixMHCpred, or MHCflurry. Implementing these strategies can augment the development of T cell receptor-based therapies by improving the identification of novel immunotherapy targets and enriching the resources available in the computational immunology field through a superior MHC presentation prediction algorithm.

Ligands↗
PubMed2025

Factors that increase class I MHC expression may contribute to the development of immune checkpoint inhibitor-induced diabetes.

Immune checkpoint inhibitors (ICIs) have improved survival of patients with cancer, yet they pose risks of immune-related adverse events (irAEs). ICI-induced insulin-dependent diabetes mellitus (ICI-DM) is a life-threatening and life-altering irAE. Previously, we reported a high incidence of a germline missense variant in NLRC5, a key class I transcription activator, among patients with ICI-DM compared with similarly treated patients who did not develop ICI-DM. Our purpose was to validate this finding in additional ICI-treated patients and study effects of the NLRC5 variant on expression of class I major histocompatibility complex (MHC) antigen presentation genes.We assessed the prevalence of the C>T missense variant at chr16:57&#x2009;025&#x2009;515 (NLRC5Pro191Leu) in germline DNA from an additional 33 patients with ICI-DM and in patients with ICI-induced colitis (n=15), ICI-induced hypothyroidism (n=19) and ICI-induced hypophysitis (n=17). The 1,000 Genomes Project was used for comparison. We assessed peripheral blood mononuclear cells from 16 individuals with or without the NLRC5 variant, studying expression of NLRC5 and select downstream target genes, before and after stimulation with interferon-&#x3b3;.We validated the higher prevalence of NLRC5Pro191Leu in a non-overlapping cohort of patients with ICI-DM compared with the general population (51.5% vs 12.8%, p<0.0001). The prevalence of NLRC5Pro191Leu in ICI-induced colitis or thyroiditis patients did not significantly differ from the general population, while the prevalence in ICI-induced hypophysitis was somewhat higher (21.6%, p=0.048). We found greater increases in messenger RNA expression of NLRC5 (p=0.007), TAP1 (p=0.0002), B2M (p=0.0005), HLA-G (p=0.04), PSMB8 (p=0.03) and PSMB9 (p=0.01) in NLRC5Pro191Leu cells stimulated with interferon-&#x3b3; compared with NLRC5WT cells. A similar trend was observed for HLA-A (p=0.09).We confirm the significantly higher prevalence of the NLRC5Pro191Leu variant in patients with ICI-DM relative to the general population. This abundance appears to be unique to patients who develop ICI-DM or hypophysitis on ICIs, underscoring its potential involvement in the pathogenesis of these endocrinopathies. The effects of this NLRC5 variant on class I MHC regulators suggest a mechanistic connection between the variant and development of ICI-DM. Further work is warranted to determine whether class I MHC molecules can be modulated in patients with the NLRC5Pro191Leu variant requiring ICIs.

Humans↗
PubMed1992

Thermal stability comparison of purified empty and peptide-filled forms of a class I MHC molecule.

A secreted form of a class I major histocompatibility complex (MHC) molecule was denatured and renatured in vitro in the absence of peptide. The resulting empty class I heterodimer was immunologically reactive and structurally similar to a heterodimer renatured in the presence of an appropriate restricted peptide. Thermal stability profiles indicated that the two forms of heterodimer differed in their resistance to denaturation by heat but that a significant portion of the empty class I heterodimers had a native conformation at physiological temperatures. Free energies calculated from these data gave a direct measure of the stabilization of the class I MHC molecule that resulted from peptide binding.

Animals↗